Crimson Heart
by MistressofSeven77
Summary: By chance, the Elric brothers meet a young girl who appears as nothing more than an innocent, lost orphan from the western part of Amestris. However, they quickly learn there's more to her than meets the eye, and begin unfolding a chaotic tale of bloodshed, psychological trauma and all kinds of scars... can the world handle the woman known as Crimson Heart?
1. Chapter 1: Innocence And Soldiers

Chapter 1: Innocence And Soldiers

"Well, I guess we're off…"

A young boy and a suit of armor were walking through Central, heading for the train station. The young boy had golden hair and golden eyes.The sun was shining brilliantly, and the sky was clear. Nothing demanded their attention-

"Oohh… Shiny!"

Ed was startled to hear the young female voice so close to him. He looked down to see a young girl right beside him, purplish eyes focused on his pocketwatch, silverish hair a bit of a mess. Her skin was white, but not deathly pale. She was wearing a simple black shirt and blue jeans, with black flip-flops.

"Stop it! It's not yours!" Ed scolded, lightly smacking her hand and pulling the object in question away. She looked up at him, eyes glistening.

"Aww… But I just wanted to look at it… I wasn't gonna take it…" She sniffled. Ed looked down at her.

"Brother, I think it's okay to let her look at it if you supervise." Alphonse said. Ed sighed.

"Alright, fine..." He relented.

"Yay!" She cheered as the trio went and sat down on a bench. Ed pulled out his pocketwatch, and handed it to her. She began tracing the elaborate design on the front, clearly fascinated.

"Do you know what that is?" Ed asked.

"Ummm... it's silver... and it's shiny... and this is the symbol of Amestris, right?" She replied, pointing to the symbol on the cover. Ed nodded.

"That's right! It's a silver pocketwatch, given to me by the military because I'm a State Alchemist!" He said.

"Oh... so you're a soldier... then how come you don't wear a uniform?" She asked.

"I've never really been comfortable in one. It's just not my thing."

"I see. Well, it's just fancy clothes. It's okay if you don't like fancy clothes."

She continued to trace the pocketwatch, fascinated by its appearance. Eventually, after a few minutes, she gave it back.

"So, anyways, what's your name? And where are you from?" Ed asked.

"Oh, me? My name is Sonata Dusk, and I'm from Sidon. What about you?" Sonata asked in turn, still cheerful, smiling.

"My name is Edward Elric, and this is my younger brother, Alphonse Elric." Ed introduced. She then cocked her head to the left in confusion. Ed raised an eyebrow.

"What's wrong?" He asked.

"I don't get it. If you're the older brother, why are you the shorter one?" She asked innocently. Ed instantly got a tic.

 _She's a kid… She doesn't know any better… She's a kid… Stay calm…. Stay calm…_ He mentally chanted, forcing the boiling rage back.

"Height doesn't always prove age, Sonata. It's not a factor-Sonata!"

Suddenly, she fell on her side, right into Ed's lap… only to immediately close her eyes and slow her breathing to a slow, steady rate. The brothers smiled softly.

"She was just tired…" Al trailed.

"I think we should bring her to the Colonel. He'll know what to do about her." He added. Ed nodded.

"That's right… I've never heard of Sidon before in my life. Al, could you carry her for me?"

"Alright."

Alphonse gently scooped up Sonata in his arms. The two brothers walked back towards Mustang's office.

* * *

The brothers barged right on in, as usual. He glanced up for a second, and seeing Ed's familiar golden eyes, he let out an exasperated sigh.

"You're going to miss your train if you stay here-"

 _THUNK._

"Owww…"

Mustang blinked. Alphonse had just dropped this kid onto his desk-literally-sending his papers everywhere and waking her up, evidently. She sat up, and looked at Mustang.

"Who are you?" She asked.

"U-Um… Colonel Roy Mustang. You?" He asked in turn.

"I'm Sonata Dusk! It's nice to meet you!" She replied cheerfully. Roy ducked his head around towards Ed.

"Umm… Fullmetal… Who is she?" He asked quietly. She turned her head, but only out of curiosity.

"I don't know. We literally found her outside five minutes ago, where she was attracted to my pocketwatch because it was shiny." Ed explained. Roy hung his head.

"Are you serious-"

"Colonel, you'd better not be slacking off again-huh?"

"Hey, chief, wanna go out tonight-what the?"

It wasn't long before Mustang's whole team had piled their way into the office. Not even someone as innocent and naive as Kain could resist the appearance of Sonata, who was currently quite confused at it all.

"Huh? Where'd all the soldiers come from? I don't get it." She asked. Roy chuckled.

"You're in Central Headquarters, Sonata. You're in the place where a lot of soldiers work." He explained. She got off his desk, and walked up to the small group. They stared at each other for a good few moments…

"You look like a puppy! Do you like puppies?"

Kain blinked, as did everyone else.

"D-Did she… Did she just seriously ask if I like puppies because she thinks I look like one?!" He stammered.

"S-She did…" Alphonse muttered.

"W-Well, she's a kid… She's just trying to be friendly…" Roy guessed. Riza chuckled.

"You like dogs, right?" She asked. Sonata nodded.

"Well, I have a dog named Black Hayate. Would you like to play with him?"

"Yea!"

Riza led the young girl out of the office to meet the adorable puppy, and instantly, she was distracted, happily chasing the dog around, petting him, and laughing. It wasn't long before somehow, Riza produced a hawk stuffed animal from seemingly nowhere, and Sonata took it gladly. Roy let out an exasperated sigh.

"Now the question becomes… what do we do with her?" He mused, leaning on his desk.


	2. Chapter 2: The Secret Buried Within

Chapter 2: The Secret Buried Within

"So, you'll take her to your teacher, see if she'll take care of her for the time being. Thanks, Fullmetal." Roy said.

"It's not a problem. Teacher has a bit of a soft spot for kids in need-I'm sure she can handle this little squirt!" Ed assured, nodding towards Sonata, who was cuddling with Black Hayate.

"We should get going-"

 _ **BANG! BANG!**_

Everyone tensed, turning and seeing that the windows to Central Headquarters were being shot out, and armed men were pouring in.

"Let's go!" Roy ordered. Everyone drew their weapons, while Roy slid on his gloves. Team Mustang charged forward, but Ed and Al hesitated.

"What about her-!"

 _ **BANG! BANG!**_

He had no time to contemplate, as bullet fire rained down on him as well, and he could see that Alphonse was being targeted. He clapped, and created a wall. Though he wanted to be concerned, he had no choice. He bit his lip.

 _If I can hurry and beat them back, it'll work out!_

He clapped and transmuted a spear, charging forward, but soon was shot in the shoulder. He cried out, as did Alphonse. Roy cursed-there were too many of them, and not enough of his men-

 _ **BAM.**_

The fighting stopped at the sound of the noise. Everyone turned, to see that Sonata was now standing up, and had slammed the hawk plushie into the ground, creating a small pit around her. Black Hayate had clearly fled at some point.

"Why…"

She stomped once on the animal, releasing a shockwave.

"Would you…"

She stomped twice, releasing two shockwaves. Everyone was staring by now.

"Shoot at good people like Mister Mustang?"

When she looked up, her gaze looked much darker. The ringleader hissed.

"They're the military! They're our enemies! We'll do whatever we want to them!" She insisted.

"So that's how it's going to be, huh…"

Everyone looked at Sonata, confused. A devilish smirk crossed her face.

"In that case…"

"GAAH!"

In an instant, a blinding light filled the area, before fading.

"Maybe _I_ should do whatever I want, too!"

Everyone looked up… only to be completely shocked and confused.

A good portion of the ceiling had been blown up, reduced to rubble. But that was not what shocked everyone.

A beautiful woman with long, bluish-purplish hair, loose bangs that draped down in her face a bit, and blood red eyes was standing there, a devilish smirk on her face. Long black sleeves with an extra bit going midway over the shoulder graced her arms with a small section fabric removed on the outer part, exposing the smooth, white skin underneath. A few small, neon pink sections were carefully laid in the sleeve. Black gloves with thin neon pink traces under the fingers covered her hands, with a neon pink circle on the backs that had two neon blue rectangles within, resting on the black within the pink. A saucer-shaped section wrapped around each wrist, the top part being black and the bottom being pink.

Around her neck was a black choker with a centerpiece in the front that had two neon pink sections on the bottom. The centerpiece was mostly black, with a thin neon pink circle, and two rectangles, the top one neon blue, while the bottom one was neon pink. Two thin black straps went down from the choker to a mostly-black bikini-like top that had a wide pink section wrapping around the lower part of her chest. Three grey buttons went down the middle, and it tapered into points that led into black straps, which led into a black bikini bottom. Two gray buttons were attached to either side of the area where the strap went into the bottom, and thick black sections led into long boots that had heels.

Her heeled boots covered most of her legs, only exposing parts of her thighs, and had a large neon pink section at the inner top part. A small neon pink rectangle rested above the knee, with a neon blue dot below it. On the front of the boot was a black diamond-like shape, resting underneath a black circle that had a raised plus-sign of the same color. A neon-pink curved section rested underneath the black circle. A set of black, butterfly-esque wings that had hollow spaces separating the outer sections and inner sections, with neon pink tips and sections inside graced her back. She finished her outfit with black, thin, circular earrings that had a neon pink rectangle inside of them. She was beautiful, and quite attractive, but something was off…

"Who the hell are you?!" The ringleader demanded.

"Me? My name is Crimson Heart." She replied confidently.

"But don't worry about memorizing it…" She continued, her expression becoming one of mocking empathy.

She clapped her hands together, and created a black metal whip that had linked, arrow-shaped sections that could interlock together to form a sword of sorts from the ruins of the ceiling. She knelt down for a moment.

" **I'm going to carve it into your fucking soul!"** She roared as she rocketed off towards the ringleader, her devilish smirk returning.

Everyone watched in horror as this new woman cracked her whip mercilessly, laughing manically as she made every single one of gunmen squirm, bleed, and cry out in agony. The ringleader looked up at her, horrified.

"W-What are you, a demon?!"

Crimson Heart laughed.

"A demon… I suppose some might call me that… Who knows? I'll contemplate it after I finish watching the life fade away from your body as my hands wrap around your throat, squeezing out every… last… drop!" She mocked, getting uncomfortably close. She kept her promise, crushing the ringleader's windpipe as slowly as she could, watching with sadistic glee as her unfortunate, hapless victim's life faded away slowly.

"What… is this? How could anyone be so cruel? She was actually _enjoying_ watching them die! She enjoyed watching them suffer!" Alphonse wondered breathlessly. No one could answer, as there really was no rationalization-

"Oh, don't be so sad, dear little Alphonse… I was _rewarding_ them!"

Alphonse was startled to suddenly see Crimson Heart so close to him, tilting his chin up to gaze into her crimson eyes.

"R-Rewarding them? F-For what?" He stuttered. She giggled.

"For letting me something so beautiful… That is, your pained expressions!" She replied, smirking. Alphonse shivered.

"W-What… Why…"

Crimson Heart continued her smirking for a while, before letting out an exasperated sigh.

"Well, I suppose that was enough fun for a while… Thanks for it, Alphonse." She said, standing back up. A blinding flash of light filled the area again, before...

Everyone blinked. They couldn't believe the figure that had appeared in place of Crimson Heart.

"Sonata...?" Alphonse wondered.


	3. Chapter 3: A Two-Sided Coin

Chapter 3: A Two-Sided Coin

"Y-You're joking with me… How is it possible?!" Roy demanded. Sonata looked at him, confused.

"Huh? How is what possible? And what happened here? The building looks like it blew up…" She wondered, attention turning to the crumbled ruins. As she began looking through the rubble, everyone else stared.

"S-She doesn't remember any of it…" Edward said, twitching in shock, horror, and fear.

"So… Crimson Heart is a split personality of hers, perhaps?" Alphonse proposed, tone nervous.

"It's the only explanation…" Roy agreed, still horrified by what he saw.

* * *

"Sidon, she says… that's an abandoned village out in the Western part of Amestris. No one's lived there for quite a few years. It was destroyed by an assault from the Aeurgian Mafia."

The Elric brothers were sitting in Roy's office, while the Flame Alchemist's team kept Sonata busy with games, stories, and Black Hayate so as to keep her from transforming yet again. Roy was leaning on his desk, head spinning from all of the chaos that had just unfolded.

"A mafia assault… so it's likely pretty much everyone else was killed…" Alphonse concluded, no less mortified by what he'd seen.

"There's no doubt… So if we want to know why she's like that…" Edward trailed, in a similar state of mind as the others who had borne witness to the events of earlier.

"We have to go to the remains of Sidon." Al finished. Roy nodded.

"With a display like that, we can't let your teacher take her. If she were to transform and go ballistic in a civilian area… I don't want to think about it. For the moment, the Lieutenant will take care of her, because she likes the Lieutenant's dog, so it should keep her calm. I'll have to think of a solution to this… it won't be easy." Roy admitted, sighing heavily. The brothers looked at Roy, concern on their faces.

"Don't worry. I'll figure something out. Go." He said, shooing them. Reluctantly, the brothers left. Roy dug his fingers through his ebony black hair, letting out an exasperated sigh.

"Why do I have a bad feeling I'm going to have to get _her_ involved…" He muttered, droning.

* * *

"Mmmm… You have a small home, Miss Riza…"

Riza chuckled as she closed the door. She'd just taken Sonata home after the end of the day, with the young girl walking Black Hayate, and not even two seconds in, Sonata already had drawn a cute conclusion about her apartment.

"Well, usually, I don't have company besides Black Hayate. But Colonel Mustang asked me to take care of you for a while, so this'll be your new home for a bit, okay?" She explained, smiling. Sonata smiled.

"Yay! I get to live with Blackie! Yay!" She beamed, running over and picking up the Shiba Inu pup. He licked her face, and she giggled, before going to play with him. Riza watched the two play with one another as she made her nightly cup of coffee, and sighed, a soft smile on her face. She sat down, continuing to watch the joyful scene unfold, with Sonata's cheerful laughter and Hayate's playful antics, an occasional bark thrown in for good measure.

 _It's really hard for me to believe that Sonata and that sadist are two sides of the same coin… They're as different as night and day!_

She frowned a bit.

 _What in the world happened to you to create such a drastically different alternate persona in you, Sonata?_ She wondered, looking down into the steaming liquid in her cup.


	4. Chapter 4: Snow, Blizzards, And A Girl

Chapter 4: Blizzards, Snow, And A Girl

The sun was shining brightly as Sonata followed Riza to the office, a joyful skip in her step. She held Black Hayate's leash, without a care in the world. As Riza walked into Roy's office, Sonata continued to follow. Riza sighed when she saw Roy, once again, ignoring his paperwork as if it wasn't there.

"Colonel, you need to work on your paperwork." She scolded. He huffed.

"I've been busy with other affairs that are more important than papers that aren't even due for _another month._ " He insisted.

"You shouldn't be lazy… being lazy is bad… And if you do bad things, you become a bad person… and bad people make me angry…"

Sonata's words were more than enough to make Roy snap to attention. He looked at Riza, and looked at her in a way that meant 'we-need-to-be-alone-this-is-serious". Riza nodded.

"Sonata, why don't you go take Black Hayate for another walk? I'm sure he'd enjoy it." Riza suggested gently. Sonata nodded.

"I'll be back!" She promised, leaving the two alone. Riza sighed, and turned back to face Roy.

"What is it, sir?" She asked.

"I was thinking last night about what to do with her, and in all honesty, I can only think of one woman who can safely handle her sadistic alternate persona without being outright _traumatized._ " Roy began. Riza's eyes widened at the hints Roy was dropped. She looked at him with a frown.

"Sir, she won't take Sonata up front. She'll see Sonata as nothing more than a burden." Riza pointed out.

"I know, but it wouldn't take much if she were up there to provoke a transformation. I've heard that Fullmetal is heading up there, which will help prove to her that Sonata isn't just some brat she can dump at Northern Command until someone picks her up." Roy said, dropping more subtle hints in his tone and expressions. Riza looked down, and let out an exasperated sigh.

"I guess we'd better go shopping for snow coats…" She droned, walking out.

* * *

"Aaah, snow! Snow, snow, snow! There's so much of it! Haha!"

Sonata happily ran out of the train station, running through the snow faster than Riza could keep up. She let snowflakes fall on her tongue, grinning like the child she was.

"Wait for me, Sonata! You'll get lost-damnit!" Riza yelled as she ran, seeing that she'd lost Sonata. She looked down and groaned.

"Somehow, I have a feeling this is going to end badly for someone…" She droned. Nonetheless, she caught her breath, gathered her bearings, and once again took off, looking for the wayward girl.

* * *

"Brrr…. It's really cold…"

Sonata, as expected, was hopelessly lost in a blizzard that had suddenly started out of nowhere. She was shivering, and was clutching her coat tight around her body. She was staggering as best she could through the thick, heavy, slick snow.

"I heard the weather changes fast in the mountains, but I don't like this… It's so cold and wet and icky…"

She looked over, blinked, and then smiled. She picked up her pace, a surge of joy hormones driving her further.

"Ah! It's Ed! ED!" She called enthusiastically. Edward and Alphonse turned, and were completely shocked to see Sonata running towards them. She tackled Ed in a bear hug, laughing gleefully.

"Sonata! What are you doing here?!" Ed demanded, looking at her.

"Miss Riza brought me here… but then I got lost… so I saw you and figured you could help me!" She explained, smiling. Ed raised an eyebrow in confusion.

"Why would Miss Riza bring Sonata up here?" Alphonse wondered.

"Ummm… I remember her saying something about a lady named Olivi… Olivia… Olivie… Um…" Sonata tried, the name's pronunciation escaping her.

"Olivier?" Alphonse corrected. Sonata nodded vigoriously.

"Yea, her! I'm supposed to meet her. Miss Riza said that she was supposed to take care of me. But why would she be up here?"

The soldiers (aforementioned Ice Queen included) and brothers all deadpanned.

"She really doesn't know…" Ed droned.

"Well, let's talk about it inside, where it isn't as cold, okay?" Alphonse suggested. Sonata nodded again, and they all went inside.


	5. Chapter 5: Big New Home

Chapter 5: Big New Home

"So, let me get this straight."

The Elric Brothers were sitting in the medical area, being interrogated by Olivier, with Buccaneer standing guard. Ed had just finished receiving his Northern automail. Olivier was clearly getting quite pissed off, if her tone and the incessant tics forming around her were to say anything.

"You two brats find this kid outside Central, and bring her to Mustang. Because of some bullshit he pulled out of his ass, he deems her too dangerous to live in a civilian residence, and so somewhere in that man-whore mind of his, he sees it fit to dump her on _me?_ " She summarized, eyebrow twitching.

"Well, it's not bullshit, it's real! That split personality of hers is the stuff of nightmares-"

" _AM I RIGHT?!"_

The brothers shrunk away at the sudden outburst. Olivier continued to death-glare at them for a while, before cursing a streak under her breath.

"That dumbass! This is a military fort, not a daycare! I don't have time to worry about some numbskull brat he finds lost outside of Central-"

"Captain, Major General, we have a problem!"

The attention universally turned to the soldier who came blazing in.

"What's the problem?" Olivier demanded.

"An unknown hostile just came out of the ground! It's some sort of giant!"

"And the little brat the little red runt brought in?"

"Her location is unknown, but she's a child, I doubt she can do anything!"

"We'll find her later. For now, we deal with that giant!"

They all tore out to the main area.

* * *

"Such a pain… Go dig a hole in the ground…. Such a pain…"

The giant was proving to be more than a match against what they had to offer. He took missiles and rockets like it was nothing, and the brothers were currently pinned under a pile of wreckage he'd created. Everyone was glaring at it-what should they do-

"That's enough… You're so annoying…"

All attention turned… to see Sonata standing right there, eyes glazed over, focused on the giant.

"Such a pain, such a pain… don't you know any other words? It's so annoying to listen to you whine and complain!" Sonata said, her tone irritated and annoyed. The Elric brothers cringed, and held each other.

"Crap, she's gonna do it!" Ed realized nervously.

"Going to do what?! What's she going to do-" Olivier began.

"But if pain is what you want…"

A blinding light filled the area, and suddenly, the giant was knocked into a wall by a powerful whip-sword slash. The black weapon was recalled back to its wielder. The brothers gripped each other tighter as a figure they'd met before was suddenly standing there, a sadistic grin plastered on her face.

"I'm more than happy to give you pain unlike anything you've _ever_ experienced before!"

"Crap, we're fucked! She transformed! Crimson Heart is here!" Ed said nervously.


End file.
